1. Field of the Disclosure
The present invention relates generally to a fluorescence imaging module, and more specifically to a fluorescence imaging module having an illuminating device capable of bending illuminating light toward the fluorescence sample.
2. Background
The technique of fluorescence microscopy has become a valuable tool in biology and biomedicine due to attributes that are not readily available in traditional optical microscopy. A fluorescence object emits fluorescence emission light after the absorption of excitation light. A variety of specimens exhibit autofluorescence when they are illuminated by excitation light. For non-autoflourescence specimens, the application of fluorophores has made it possible to identify cells and sub-microscopic cellular components with a high degree of specificity. The added fluorophores are excited by illuminating light having an excitation wavelength and emit light having an emission wavelength, which is longer than the excitation wavelength. Fluorophores are stains that attach themselves to target structures. The widespread growth in the utilization of fluorescence microscopy is closely linked to the development of new synthetic and naturally occurring fluorophores with known profiles of excitation and emission, along with well-understood biological targets.
An example of a fluorescence microscope 100 is depicted in FIG. 1. A white light emitting diode (LED) 102 illuminates a fluorescence sample 104 on a microscope slide. A microscope objective 106 in combination with a tube lens (eyepiece) 108 acquires an image of sample 104 on an image sensor 110. An ultraviolet LED 118 and a blue LED 116 are used to illuminate sample 104. The illuminating light having the ultraviolet and blue wavelengths excites sample 104 such that sample 104 emits fluorescence light. Sample 104 may exhibit autofluorescence or may have been stained with fluorophores. Excitation filters 122 and 120 filter the excitation light emitted by ultraviolet LED 118 and blue LED 116, respectively. The light beams after passing excitation filters 120 and 122 are combined by a first dichroic minor 114. The combined excitation light beams from ultraviolet LED 118 and blue LED 116 are reflected by a second dichroic minor 112 to illuminate sample 104. The emitted fluorescence light from sample 104 is transmitted through second dichroic mirror 112, passes through an emission filter 124, and forms the image of fluorescence sample 104 on camera 110.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.